The present invention relates to measurement of the performance of a serial digital data link, and more particularly to a method of error detection/concealment for serial digital video that operates in-service without any special data coding.
Currently the Digital Serial Standard for transferring either composite or component digital video is subject to debate. The proposed Digital Serial Standard uses a scrambler/descrambler to lower the DC component of the serial data stream and to facilitate clock recovery. A measure of the performance of the serial digital transfer link is needed to determine threshold headroom. Bit Error Rate (BER) is an industry standard measure of link performance, especially when the link is not "bursty" or data dependent. However, BER testers are usually used out-of-service since they must source test data to stress the link.
Recently a new method has been proposed, as disclosed in U.S. Pat. No. 5,208,666 issued May 4, 1993 to Robert Elkind et al entitled "Error Detection for digital Television Equipment", that entails inserting a Cyclic Redundancy Code (CRC) in every field at a transmitting device to allow a receiver to determine, among other things, if one or more bit errors have occurred in the field. This allows BER determination up to about an average of five errors/field and requires that all transmitting and receiving devices have the encoding and decoding hardware installed.
What is desired is a method of error detection/concealment for serial digital video that operates in-service without any special data coding required.